scholarly journals Complex Tasks Force Hand Laterality and Technological Behaviour in Naturalistically Housed Chimpanzees: Inferences in Hominin Evolution

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
M. Mosquera ◽  
N. Geribàs ◽  
A. Bargalló ◽  
M. Llorente ◽  
D. Riba
Keyword(s):  
Human Evolution ◽  
Tool Use ◽  
Task Complexity ◽  
Complex Behaviour ◽  
Hominin Evolution ◽  
Hand Laterality ◽  
Complementary Role ◽  
Interesting Connection ◽  
The Difference ◽  
And Task

Clear hand laterality patterns in humans are widely accepted. However, humans only elicit a significant hand laterality pattern when performing complementary role differentiation (CRD) tasks. Meanwhile, hand laterality in chimpanzees is weaker and controversial. Here we have reevaluated our results on hand laterality in chimpanzees housed in naturalistic environments at Fundació Mona (Spain) and Chimfunshi Wild Orphanage (Zambia). Our results show that the difference between hand laterality in humans and chimpanzees is not as great as once thought. Furthermore, we found a link between hand laterality and task complexity and also an even more interesting connection: CRD tasks elicited not only the hand laterality but also the use of tools. This paper aims to turn attention to the importance of this threefold connection in human evolution: the link between CRD tasks, hand laterality, and tool use, which has important evolutionary implications that may explain the development of complex behaviour in early hominins.

Are tool properties always processed automatically? The role of tool use context and task complexity

Cortex ◽  
2013 ◽  
Vol 49 (6) ◽  
pp. 1679-1693 ◽  
Author(s):  
Jennifer Randerath ◽  
Kimberley R. Martin ◽  
Scott H. Frey
Keyword(s):  
Tool Use ◽  
Task Complexity ◽  
Use Context ◽  
And Task

scholarly journals The loss of the ‘pelvic step’ in human evolution

2021 ◽  
Vol 224 (16) ◽  
Author(s):  
Nathan E. Thompson ◽  
Danielle Rubinstein ◽  
William Parrella-O'Donnell ◽  
Matthew A. Brett ◽  
Brigitte Demes ◽  
...  
Keyword(s):  
Human Evolution ◽  
Stride Length ◽  
Sagittal Plane ◽  
Human Walking ◽  
Pelvic Rotation ◽  
Hominin Evolution ◽  
Speed Range ◽  
The Difference ◽  
Wide Speed Range

ABSTRACT Human bipedalism entails relatively short strides compared with facultatively bipedal primates. Unique non-sagittal-plane motions associated with bipedalism may account for part of this discrepancy. Pelvic rotation anteriorly translates the hip, contributing to bipedal stride length (i.e. the ‘pelvic step’). Facultative bipedalism in non-human primates entails much larger pelvic rotation than in humans, suggesting that a larger pelvic step may contribute to their relatively longer strides. We collected data on the pelvic step in bipedal chimpanzees and over a wide speed range of human walking. At matched dimensionless speeds, humans have 26.7% shorter dimensionless strides, and a pelvic step 5.4 times smaller than bipedal chimpanzees. Differences in pelvic rotation explain 31.8% of the difference in dimensionless stride length between the two species. We suggest that relative stride lengths and the pelvic step have been significantly reduced throughout the course of hominin evolution.

Motivational arousal and task complexity.

1970 ◽  
Vol 83 (2, Pt.1) ◽  
pp. 329-330 ◽  
Author(s):  
Peter Suedfeld ◽  
P. Bruce Landon
Keyword(s):  
Task Complexity ◽  
And Task

Information processing rates and task complexity.

1970 ◽  
Vol 83 (1, Pt.1) ◽  
pp. 131-135 ◽  
Author(s):  
Richard W. Olshavsky ◽  
Lee W. Gregg
Keyword(s):  
Information Processing ◽  
Task Complexity ◽  
And Task

Kinematic contribution and synchronization of the trunk, hip, and knee during free-dynamic lifting

2003 ◽  
Vol 3 (2) ◽  
pp. 99-108
Author(s):  
Kermit G. Davis ◽  
Riley E. Splittstoesser ◽  
William S. Marras
Keyword(s):  
Whole Body ◽  
Knee Height ◽  
Squat Lifting ◽  
The Difference ◽  
Free Dynamic ◽  
Body Lifting ◽  
And Task ◽  
Kinematic Contribution ◽  
Stoop Lifting

Although there have been numerous studies evaluating the difference between stooped and squat lifting styles, there remains a lack of understanding of whole body kinematics during unrestricted lifting. The current study evaluated nine males and nine females while lifting two box weights (9.1 kg, 18.2 kg) from five origins below the waist (0, 19, 38, 57, and 76 cm above the floor) and from three task asymmetries (sagittally symmetric, 45° clockwise, 45° counter-clockwise). While the lifting style was significantly influenced by the height of lift origin and to a lesser extent gender, box weight, and task asymmetry, none of the conditions resulted in pure squat or stoop lifting style. However, for lifts above knee height, the lifting style resembled more of a stoop lift while lifts originating below knee height were more of a squat lift. As the origin moved closer to the floor, participants relied more on their hips to accomplish the sagittal flexion but overall adopted a more coordinated whole-body lifting style. All together, as more sagittal flexion is required, more joints are relied upon in a more coordinated effort. The current study indicates that caution needs to be exercised when applying results of pure squat or pure stoop lifting studies to free-style (realistic) lifting.

Research Note: The Interactions Among Stress, Vigilance, and Task Complexity

1975 ◽  
Vol 17 (1) ◽  
pp. 106-109 ◽  
Author(s):  
Robert S. Kennedy ◽  
Xenia B. Coulter
Keyword(s):  
Task Complexity ◽  
Vigilance Task ◽  
Research Note ◽  
Stressed Condition ◽  
Complex Task ◽  
Large Group ◽  
Flight Students ◽  
Better Than ◽  
Threat Of Shock ◽  
And Task

A simple (one-channel) or a complex (three-channel) vigilance task was administered with or without threat of shock to a large group of flight students. It was found that a larger absolute decrement was obtained in the complex task, but the relative decrements were equivalent for both. One-channel monitoring was better overall than three-channel monitoring in the non-stressed condition. Stressed subjects performed better than nonstressed, and this enhancement was greater for three-channel monitoring.

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